Exhaust steam injector



Filed Ma rch 7, 1934 3 Sheets-Sheet l INVENTOR EMANUEL PAM/501v. Wm/wATTORNEY May 21, 1935.

E. RAWSON EXHAUST STEAM INJECTOR Filed March 7, 1934 5 Sheets-Sheet 5ATTORNEY.

Patented May 21, 1935 fomrsos'rATEs r -Artur OFFICE,

EXHAUST STEAM INJECTOR Emanuel l tawson, North Bergen, N. J., assignorto The Superheate'r Company, New York, N. Y.

stApplication'March '7, 1934, Serial No. 714,384

y 9 Claims. (01. lot-2 The presentinvention relates to exhaust steam"injectors and has particular reference toexhaust steam injectors of thetype adapted to be applied boiler feeding devices for locomotiveboilers. Still more particularly the invention relates to exhaust steaminjectors of the above-character 'aiidcontrol systems therefor adaptedtobe ac tuated by the pressure of live steam admitted tothe*locomotiveengine for automatically causing th e i'njector tobeoperated wholly by live steam when exhaust steam from the locomotiveengine is not available and for causing the injector to beoperated'byexhaust steam from the'locomo- 'tive engine when such steam isavailable.

Control systems actuated by the-pressure of live steamadmitted to alocomotive engine for causing such automatic change in operation ofexhaust steam injectors are known broadly and have been utilizedcommercially with varying degrees of success. Practical experience withsuch injectors and control systems has demonstrated that certainundesirable characteristics of operation occur in practical servicewhich wouldnot be expected from a theoretical consideration of thefunctioning of the apparatus, and it is one of the principal objects ofthe present invention to improve upon the construction of a live" steamactuated control or change-over system so as to eliminate the faults inoperationwhich practical experience has shown to exist in previoussystems of the character under discussion.

One of the principal functions of exhaust steam injectors, as applied tolocomotives, is to conserve fuel by returning to the boiler as much aspossible of theexhaust steam from the engine, which heat' is recoveredby condensation of the exhaust steam in the injector. Experience hasproved that under practical operating conditions, certain combinationsof operating-facjtor's may arise which render operation of an injectorby exhaust steam undesirable, if not impossible, and control systemsheretofore developed have provided means whereby under the "control ofthe operator the injector may be positively shiftedto live steamoperation in spite of the presence of'high pressure steam in the enginesupply line which would normally 'act to shift the injector to exhauststeamopera'tion.

3 Experience has shown that with a control system provided with aso-called emergency position which insures operation of the injector asalive steam injector, regardless of the presence or absence of exhauststeam, the tendency of the operators of the injectors is, if theinjectoris once 1 shifted to the'emergency position, to .iorgetto i2.mounted ,below the cab and is supplied witha through pipe IA.

returnthe control system to a normal operating position-and to allow itto continue to operate in the emergency. -It is evident that with theconoperator that the injector is not functioning in its normallyintended manner to make use of exhaust steam when such steam isavailable.

Other andmore detailed objects of the invention and the manner in whichthe above general and detailed objects thereof are attained may best beunderstood by the ensuing description of suitable forms of apparatus forcarrying the invention into eifect, taken inv conjunction with theaccompanying drawings forming .a part of this'specification, in whichFig. 1 is a .mOre' or less. diagrammaticelevation of part of alocomotive showing injector ap- .25 paratus embodying the presentinvention;

. Fig. 2 is a more or less diagrammatic section on, alarger scaleshowing part of the injector and the valve apparatus illustrated in Fig.1; i

Fig. 3 is a view similar to Fig. 2 showing a. diiferent form ofapparatus; and

Fig. 4 is a view on a still larger scale'of .part of the apparatusshown'in Fig. 3.

In Fig. 1 the boiler of the locomotive is indicated generally at landthe operators cab at .3

The injector indicated generally at A is water from the engine tender(not shown) .Overflow from the injector during priming periods passesthrough the over- 1 flow pipe i6 and water is delivered by the injectorto thelboiler through the delivery pipe 18. Exhaust steam for operatingthe injector is conducted from a suitable place in the exhaust passageof theengine cylinder 2E! through the exhaust steam supply pipe .22, andlive steam. for actuating. certain parts of the control system and foroperating the injector is supplied from the boiler turret .24 throughthe pipe 26 .in which is located the main control valve B, the latter 5being connected withthe injector by means of the steam supply pipes'28and 30. Valve B is provided with. an manual control in the form. of

a hand wheel .32 located in the cab [2. Also located in cab |2,is thewater control handle 5 the supply pipe I4. .to the injector iscontrolled by moving nozzle 34 for governing the amount of watersupplied to the injector. Mounted adjacent to the main control valve Bis the automatic or change-over valve C, the function of which will beexplained later. This valve is connected with the injector body by meansof pipe 36. The change-over valve C is connected by means of pipe 38 toa relay valve D which is in turn connected to the steam chest of theengine cylinder 20 or to the steam supply line leading to the steamchest by means of pipe 40. Live steam from the pipe 28 is supplied tothe relay valve through pipe 42 and a vent pipe 44 connects the body ofthe relay valve with the body of the injector. Pipe 4'6 leads from therelay valve body to the interior of the cab I2 and is provided withamanually controlled valve 48. The discharge from valve 48 is open to theatmosphere at 50 and fluid discharged at 50, when valve 48 is open, iscaught in a suitable pan or funnel 52 from which it is conducted throughthe drain pipe 54 to the .ash pan of the locomotive or other suitableplace.

Relay .valve D is also vented to atmosphere or other suitable zone oflow pressure by pipe 56.

Turning now to Fig. 2, in which the parts are shown in section, theinjector illustrated is of known type and comprises a housing providinga main low pressure steam chamber 53 'to which exhaust steam is admittedfrom pipe 22 under the control of the exhaust valve 60. .Valve 60 isclosed by spring 62 and is opened by live steam pressure acting onpiston 04. Steam is admitted to piston 64 from pipe 36 leading from thechange-over valve C.

Steam from chamber 58 flows to the main low pressure steam nozzle andwater is admitted from the chamber 68 which is in communication with Theamount of Water fed 66 longitudinally of the injector body by means ofthe control apparatus comprising the rotatably mounted spindle having aneccentrically mounted pin I2 engaging a suitable recess in nozzle 66.Spindle i0 is connected by means of 'so as to move longitudinally withthe threaded control spindle '18 which carries the hand wheel A secondvalve head 80 is connected to the valve head it by means of a suitablelost motion connection 82. Valve head 16 controls flow of steam frompipe 26 to chamber 84, the latter being connected by means of pipe 28and passage 88 in the injector to the high pressure steam nozzle 88.Nozzle 88 will hereinafter be referred to as the supplementary steamnozzle and the steam supplied therethrough will be referred to -92forming a restriction or throttling orifice at the inlet of chamber 90.

The automatic or change-over valve C comprises a valve member 94 havinga double faced valve head 96 seating alternatively against upper andlower valve seats formed in chamber 98, which chamber is incommunication with chamber 90. Valve member 94 has a piston I00 looselyfitted in "the cylindrical chamber I02 and above this piston thereislocated the check valve I04 seating to close com munication betweenchamber I02 and a chamber I06 with which pipe 38 communicates. Belowchamber 98 there is provided the chamber I08, placed in communicationwith chamber 98 by means of passage H0. Chamber I08 is in communicationwith the inlet of pipe 30. Pipe 30 is in communication by way of thepassage H2 and ports I I4 with the main steam chamber 58 of theinjector;

The change-over valve member 94 is preferably provided with a suitablelower guide piston H0.

The apparatus which has been described above in detail constitutes oneform of a live steam pressure actuated control system of a type which isknown and Which in prior installations has been actuated by admittingsteam directly from the engine steam chests to the chamber I06 through apipe such as 38 shown in Fig. 2. In order to better understand thepresent invention, the operation of this portion of the apparatus, whichconstitutes prior art structure, and the nature of the faults in theoperation thereof will now be explained.

Let it be assumed that the locomotive engine is running and exhauststeam for operation of the injector is available. Let it also be assumedthat the main control valve B is open as shown in Fig. 2. With the valvehead 76 open, supplementary steam at high pressure will be admitted tonozzle 88 and through a suitable known type of connection (not shown) awater valve controlling the flow of water to chamber 68 of the injectorwill be opened. The high pressure supplementary steam and the water willserve to prime the injector.

Valve head 80, being open, permits live steam to flow to chamber 98, andvalve head 96 being in the lower position shown in Fig. 2, live steamflows to chamber I02 and through pipe 30 to the exhaust valve piston 64,thus opening the exhaust valve and permitting exhaust steam to flow tochamber 58 and the main low pressure steam nozzle 66. With the valvehead 96 in its lower position, flow of live steam to chamber I08 andconsequently through pipe 30 to the steam chamber 58 is prevented.

Under the conditions assumed, live steam from the engine steam chests isadmitted through pipe 38 to chamber I66 and seats the check valve I04.Due to the fact that piston I00 is a loose fit in chamber I02, steamleaks past this piston to balance it and with this piston balanced theunbalanced pressure of steam in chamber 98, acting on the valve head 96,serves to maintain the change-over valve member 94 in its lowerposition.

With the parts in the position described the injector functions as anexhaust steam injector utilizing exhaust steam from the engine and asmall amount of high pressure supplementary live steam, the latter beingsupplied at all times when the injector is in operation. If we nowassume that the engine throttle is closed so that exhaust steam is nolonger available, the action is as follows:

Steam pressure in pipe 38 fails and the steam in chamber I06 and in thespace between the check valve and piston I00 is vented to the enginesteam chests through pipe 38. Release of pressure above piston I00causes this piston to become unbalanced and to lift the change-overvalve member 94 so that valve head 06 seats against its upper seattoclose communication between chambers 98 a '0 an Open com n ca i n by rof i s ls passage H0, for flow of steam from chamber 98 to t e upply p p8 an to th m in s em h h r .8 oi h 'i iec o At th a e t m i t the loosefit of piston I00, steamiromthe pipe 36 es a s t p p s m in t e exhausva v (0 to clos n r th i uen i S n 62 When valve head 96 is on itslowersealt there is n flo f steam ii'o h m er 12 xc p ior the leakageflow past the clearance space around piston lljl lto the steam chests ofthe enginewhich always have a somewhat lower pressure thanboilerpressnre when the engine is running) and con.- sequently thepressure in this chamber 15 substantially equal to boiler pressure, butwhen the changerover' valve shifts so as to open communication to thechamber ifiiif for flow of steam to the injector, the pressure of thesteam admitted to chamber 98 is reduced bythe throttling action "of therestriction 92, so that the live steam admitted through pipe 33 to the.injector is ad.- mi t d the at a r su a xi a i av rage exhaust steampressure. This live steam of reduced pressure will hereinafter bereferred to as auxiliary steam.

vViihen the valve head 96 is seated. in its upper position, it will thusbe evident that the lower faceof this valve is exposed to. the pressureof steam of only relatively low pressure. Consequently, when the enginethrottle is again opened and high pressure steam from the steam chestsis admitted to chamber Hit, the pressure exerted on the upper face ofpiston Hill is ample to cause shifting of the valve back to its lowerposition. Qheck valve I04 does not interfere with the admission of steamto piston i013 since when the valve member 94 is in its upper position,the check valve HM is mechanically lifted from its seat.

For purposes of considering operation of the system,'check valve Hi4.may be disregarded. This valve is provided only for the purpose ofpreventing leakage of live steam past piston H10 and into the. injectorduring periods when the engine is running and the injector is not inoperation.

In order to have satisfactory practical operation of the injector, it ishighly desirable that the control system effect chan eeover of operationof the injector from livesteam to exhaust steam and vice versa when the'most favorable conditions obtain for such change-over. highly desirablethat the change-over be consistent. From a consideration of the mode ofoperation described above, it will be evident that the controllingfactor in the change-over of,-operation is the difference in pressurebetween the two ides of the. vi n "3 of the h e over valve. By way ofexample, let us assume ,hat the injector isloperating on exhaust steamand; that itis desired to have the injector shift over to, live steamoperation when the engine throttle is closed to an extent such that thepres.- e, of the-exhaust steam from the engine falls to a value of onepound or less above atmospheric. This condition of exhaust steampressure will be represented by a corresponding relatively low s eamchest re u e a d on e l a a iv iv in r ss re in i e 8- e i b um d thatthepressure pipe 38for this condition is 100 p unds e q ar n h-a d thath p es u of ive. steam from the boiler in chamber IQ? is 200 pounds persquare inch. As the pressure in pipe 38-. drons om ts no m l P r o avalu s de ab be o t t chamb r 02 fl of h P essur e m mm c a ber It? tope 38. comm n s nd h ressu n chamb -1 6' nd 1 .1-

Experience has shown that due to unavoidable wear and other practicaloperating factors the amount of steam flowing past piston I00 cannot bekept constant over long periods of operationand consequently for a givensteam chest pressure at the outlet of pipe 38 there maybe variations ofconsiderable magnitude in the pressure in chamber I06, 7 whichvariations obviously effect the change-over of the system from one typeof operation to the other. Many attempts have been made heretofore tocorrect the difficulties encountered withthe type of valve underdiscussion due to the variations in its action, but long experience hasshown that to change the construction in the diiferent ways'heretoforeproposed leads to other difliculties in operation more disl advantageousthan the diff culties sought to be remedied. Systems of the generalcharacter under discussion are comparatively very sensitive in operationand the relatively great number of factors which must be properlycorrelated renment under discussion is the fact that in locomotiveinstallations, the injector is usually located adjacent the cab andconsequently the pipe 38 leading to the steam chests is relativelylong,and also, because of practical considerations, is of relatively smalldiameter. It has been foundin' service that this pipe at times maybecome par.-

tially restricted due to foreign matter suchas' scale, rust or the likein the pipe, and frequently becomes partially restricted due to the pipebecoming dented. Since, in practical installations,

this pipe is frequently placed beneath the outer insulating cover of theboiler, it is extremely diflicult to reach and restrictions in it maynot be known. Any restrictions in this pipe which are of sufhcientmagnitude to materially alter the pressure drop between the ends of thepipe have the same effect of varying the steam chest pressure at whichthe injector changes over as does the wear in the valve whichorders therate of flowpast the piston I00; The present invention eliminates thedifficulties heretofore encountered with apparatus of the characterdescribedand provides further advantages not obtainable with a para h fe used, a im e ma ine and in a way such that the invention is readilyapplicable to existing installations as well as being applicable to newequipment. i

The use of the invention in apparatus of a form applicable forinstallation with existing apparatus is shown in the embodimentillustrated in Fig.2. In this embodiment there isinterposed between thepipe 41) leading from the engine steam ch st and h ipe 38. c n ct d tothe chamber H16 of the change-over valve, the relay valve mechanismindicated generally at D. This mechanism comprises a relay valve member[L8 having a double faced head [2 0 located in chamber I22 with whichpipe 38 communicates. When the valve head I2!) is seated against thelower valve seat cooperating therewith, communication is closed betweenpipe 38 and the vent 55 and commumcation is established between pipe, 38and chamber I24 which is, connected by means of pipe 42 with the highpressure steam supply pipe 28, The relay Valve member [L8 is provided atits upper end with a piston I26 slidably mounted in the valvehousingandhaving a small leak passage I28 passing therethrough. Passage I28provides constant communication between chamber I24 and a chamber I30located above piston I26. Restricted communication between chambers I24and I39 may be provided by other means such, for

'instance, as a small passage in the valve housing ,or a clearance spacebetweenpiston I26 and the housing. chamber I32 by means of a vent portI34 and Chamber I30 is connected with chamber I32 is vented by means ofpipe 45, preferably to the low pressure steam chamber of the injector.Vent port I34 is controlled by the vent valve I36 which is in the formof a plunger, the upper end of which is located in chamber I38.

Pipe 40 connects chamber I38 with the engines Vent valve I36 is Aspreviously explained, the operation of the injector on exhaust steam orauxiliary live steam is determined by the presence or absence of :steamof predetermined pressure in chamber I86 of the change-over valve, andthe relay valve arrangement just described operates to control thepressure in this chamber in the following man- 30 j Let it be assumedthat the injector is in opcration and that the engine of the locomotiveis running." Whenever the main control valve B is open, that is,whenever the injector is operating,

high pressure live steam is supplied through pipe 42 to chamber I24 and,if the valve head i 28 is in the lower position shown in the figure,this high pressure live steam flows through chamber H22 and pipe 38 tothechamber i86 causing the change-over valve to assume the properposition -'for' exhaust steam operation. The position taken 'by therelay valve member H3 is determined by 'the presence or absence ofpressure inchamber 'I3Ilabove piston I26. If pressure isbuilt up inchamber I39 soas to balance the piston I25, the valve will assume theposition shown in the figure and, if the pressure in chamber I33 isreleased, the pressure of steam in chamber I24, acting on the lower faceof the piston, will lift the valve member I I8 so as to seat the head52!; in its upper position. In this position of the valve head, thesupply of high pressure steam from pipe 42 to chamber IE6 is cut off andchamber we is simultaneously vented to atmosphere through the ventconnection 55. When pressure is released from chamber Itilfthechange-over valve, as previously described, shiftsto changeopera tion ofthe injector to live steam operation;

Due to the presence of the leak passage I 28 through piston I25, chamberI3!) is in communication with a source of high pressure live steam atall times when the injector is in operation and the presence or absenceof a pressure in chamber ISBis determined by the position of the ventvalve I36 (assuming the valve 48 in the cab for controlling the pipe M5to be closed). As will be evident upon the drawings, the vent valve Iwill be closed when pressure in chamber I38 oi steamadmitted theretofrom the steam chest or supply pipe through pipe is sufiicient toovercome the spring Mi] and the pressure exerted on the lower face ofthe valve when the, valve is closed.

The above described relay valve arrangement operates to eliminate thedifliculties heretofore encountered and the possibility of change overof the injector at varying steam chest pressures, for

the following reasons:

Piston I00 of the change-over valve is actuated by a supply of highpressure steam flowing substantially directly from the boiler and ofrelatively constant pressure.- While the boiler pressure may vary, itnevertheless is practically at all times at relatively high pressure,and even under conditions when the boiler pressure is abnormally low sothat the pressure in chamber 506 is considerably below normal, thecondition of low boiler pressure also reduces the pressure of the steamacting on the valvemember 94 in opposition to the pressure in chamberH36 so that variations in boiler pressure may for practical purposes beneglected. The previously employed long pipe connection from thechange-over valve to the steam chests is'eliminated and in place of thislong connection there is substituted the short and relatively'freeconnection for venting the chamber I86 which comprises the pipe 38connecting the change-over and relay valve housings and-the directatmospheric vent from chamber I22 by way of pipe 56, which pipe may bevery short and which, if desired, may be omitted (entirely, since the'amount of steam escaping vtheretlu'oughbeforethe automatic valve shiftsto seat in its upper'position is very small. Thus,

'with the present arrangement, chamber Hi6 may be said to be freelyvented to atmosphere and any increase in the amount of steam passingpiston I80, due to wear in this piston, does not affect the pressure inchamber H36 because of the free venting of this chamber to theatmosphere. In practical operation the action of the apparatus is suchthat the change-over valve shifts substantially simultaneously inresponse to shift of position in the relay valve head I20, re-

gardless of variations in clearance in the changeover valve mechanismdue to wear or other causes. Due to the fact that steam from chamber I30of the relay valve. is vented through pipe 44 and does not have topassthrough the long pipe 49 leading to the engine cylinders, the amount ofsteamilow through pipe '45) necessaryto close the vent valve E36 or torelieve the pressure in the small chamber I38 so as to permit this ventvalve to open, is so small that restrictions in pipe 48 which may occurin service have little, if any, effect upon the steam chest pressurerequired to effect opening or closing of the vent valve with any givenadjustment of spring I46). Thus, instead of an apparatus which inservice may cause change over of operation of the injector at differentsteam chest pressures, which is highly undesirable, there is provided inaccordance with the present invention an apparatus which willconsistently eifect change overof the injector at the steam chestpressure for which the apparatus is set. Furthermore, the apparatusprovided by the present invention permits, through the adjustment of thetension on spring me, 'an accurate control of the steam chest pressureat which the apparatus will function to effect change over .advantageouspressure for any given locomotive to which the injector apparatus may beapplied. Thisfeature of readyadjustability is not possible of attainmentwith prior systems.

Considering now.the matter of the provision ofan emergency position.whereby the injector may be caused to operate as a live steam injectorat the will of the operator, regardless of the presonce or absence ofexhaust steam,'it will be evidentuthat if the valve 48 in the cab isopenedby the operator, chamber I of the relay valve will be vented toatmosphere through pipe 46 regardlessof whether or not the vent valveI36 is opened or closed. If valve 48 is open, the action of the relayvalve will be the same asif the vent valve I36 had been opened byfailure of pressure in pipe40; the change-over valve will consequentlybe shifted to auxiliary live steam operating position, and thechange-over valve will remain in this-position so long as valve 48 isopen. However, when valve 48 is open, steam from chamber I24. leakingconstantly through the passage I28 to chamber I30 and normally passingthrough pipe44 when valve I36 is open, flows to atmosphere'in the cab at50. This constant supply of steam, although relatively small inquantity, provides a constant and annoying reminder to the operator thatthe injector is in emergency position and, as a result, the operator canbe depended upon, as soon as the conditions requiring emer-[ gencyoperation have ceased to exist, to close valve 48 and thus restore thecontrol system to normal operation in which exhaust steam will beutilized when it is available.

Turning now to Figs. 3 and 4, another form of apparatus embodying theinvention is shown, in which the separate change-over valve and relayvalve structures of Fig. 2 are dispensed with and a combined change-overand relay valve arrangement is substituted.

In Fig. 3 the form and arrangement of the injector A and the maincontrol valve B are the same as that previously described, except thatin the control valve the choke or throttling member 92 is dispensedwith.

In the present arrangement chamber 90 of the main control valve is incommunication with a chamber I50 which is connected with chambers I52and I54 by passages I56 and I58, respectively. A double headedchange-over valve I60 is arranged with a lower piston-like head I62located in chamber I52 and an upper, double facedhead I64 located inchamber I54. Chamber I52 communicates with the auxiliary steam supplypipe 30 in which is located an adjustable restricting valve I66 forreducing the pressure of auxiliary steam flowing to the injector.Chamber I54 communicates with chamber I 68 by way of passage I 10 and isalso placed in communication with the exhaust .valve operating piston 64by pipe 36. Chamber I68 is vented to atmosphere'or other zone of lowpressure by pipe 56. Below the piston head I62 is chamber I12 whichcommunicates by way of the vent port I14 with chamber I16. Pipe 46leading to the emergency control valve 48 in the cab also communicateswith chamber I12. Pipe 44 vents chamber I16, preferably to the lowpressure steam chamber of the injector.

Vent port I14 is controlled by the vent valve I18 carried by diaphragm Iand urged toward open position by spring I82, the tension of which ispreferably made adjustable as indicated. Below the diaphragm I80 thecasing structure provides a chamber I84 in communication with chamberI86 by way of ports I88. Chamber I86 is connected by pipe 40 to thesteam supply line of the engine. The details of construction of the formof. valve head I62 are shown on an enlarged scale in Fig. 4. .As shownin this figure, the lower valve head I62 is loosely mounted on the stemof the valve member I60 between collars I90 and I92 so communicationbetween chambers I52 and I12,

which restricted communication, may be pro.-

vided by other specific forms of passages. The operation of this form ofapparatus is as follows:

The presence or absence of steam from the supply line to the engine inchamber I84determines the position of the vent valve I18 andconsequently determines the presence or absence of pressure in chamberI12, to which chamber-a restricted quantity-of steam can flow by way ofthe clearance spacev I64 and recess I96. The presence or absence ofpressure in chamber I12 determines the position of the change-over valveWhen the engine is not operating and chamber I12 is vented through portI14,-the pressure of steam in. chamber I50 acting on the upper face ofhead I 62 over-balances the pressure acting in the opposite direction onthe smaller upper head I64 and the valve assumes the position, shown inthe drawings so as topadmit auxiliary steam to the injector. In this.posi-' tion of the change-over valve,.head I64 seats to close passageI58. thus cutting off the supply of actuating steam supplied to theexhaust valve from chamber I54 by way of pipe 36. At the same timechamber I54 is vented to, atmosphere by way of passage I10 and pipe 56,thus releasing all pressure from pipe 36 so that the exhaust valve canclose. With the changeover valve member in this position, high pressurelive steam can, as previously pointed out, leak past the head I62 to thechamber I12 so that when the admission of steam to the engine supplyline causes the vent valve I18 to be closed, pressure will build up inchamber I12 to over-balance the change-over valve and cause it to moveto its upper position.

In its upper position the-upper valve head is shifted to close passageI10 and to open passage I58 so as to admit actuating steam to theexhaust valve piston 64 and cause the exhaust valve to be opened. At thesame time the seating of the lower head I62 closes passage I56connecting chambers I50 and I52 to shut ofl the supply of auxiliary livesteam to the injector. In the upper position of the change-over valvemember it will be evident that both'the upper face of the upper head I64and the upper face of the lower head I62 must seat and in order toinsure proper seat-. ing of both of. these heads, theyare preferably.not rigidly connected to each other.

It will be evident that the arrangement just described provides thesame'advantages over ex-. isting systems as the arrangement shown inFig.

2. The construction does not involve the flow 7 since allof thepressures affecting the positioning of the valve are derived from thesame sourcepf steam supply. As in the formshown Fig-.12;

the convenient emergency feature is readily jobtained by placing thechamber I12 in communication with the pipe 46 leading to the engine cab.Also, ready adjustability ofthe steam chest pressure at which theapparatus will effect changein operation of the injector is provided bythe simpleadjustment of the tension of spring I82 acting on the ventvalve H8.

From the foregoing description it will be evident that the presentinvention may be embodied in widely diiierent forms of apparatus and itis therefore to be understood that the invention is in no way limited'tothe forms of construction shown herein by way of example nor is it to beconsidered as being limited in its application to the specific forms ofinjector and control system shown herein.- For-example, it is evidentthat the invention is equally applicable to exhaust steam injectors ofthe multiple-stage type wherein instead of utilizing supplementary highpressure steam in the same stage of the injector as the low pressuresteam, the high pressure steam is employed in a separate'high pressureor boosting stage. Also, in installations where the injector is intendedto deliver only against relativelylow pressure and auxiliary live steamalone is sufiicient without the aid of supplementary live steam in anyform, the present invention is equally applicable.

It is further to be understood that certain features of the inventioncan be employed to the exclusion of others and the invention is to beconsideredas embracing all such forms of. construction 'as fall withinthe scope of the appended claims when construed as broadly as isconsistent with the state of the prior art.

What I claim is:

1. In a feed water system including an exhaust steam injector forsupplying water to a steam generator which supplies steam to a steamconsumer,said injector being of the type adapted to be operated byauxiliary live steam when exhaust steam from said' consumer is notavailable, a control system for changing from exhaust steam to auxiliarylive steam operation including a valve for controlling admission ofauxiliary live steam to theinjector, a connection providing a path forflow of pressure fluid from a source of relatively high pressure to azone of relatively low pressure, means responsive to variations ofpressure in said connection for controlling the position of said valve,valve means for controlling flow through'said connection for varying thepressure 1 therein, and means responsive to variations in the pressureof steam supplied to said consumer for operating said valve means.

2. In a feed water system'including an exhaust steaminje'ctor forsupplying water to a steam l generator which supplies steam to a steamconsumer, said injector being of the type adapted to be operated byauxiliary live steam when exhaust steam from said consumer is notavailable, in combination therewith, a control system for changing fromexhaust to live steam operation including a valve for controllingadmission of auxiliary live steam to the injector, a connectionproviding a path of flow of steam from said generator to a zone of lowerpressure, means responsive tovariations of pressure in said connectionfor controlling the position of said valve, valve means for controllingflow through saidconnecltion'for varying the presure therein, and meansresponsive to variations in the pressure of a steam supplied to' saidconsumer for operating to be operated'by auxiliary'live steamwhenexhaust steam from said consumer is not available,"

a control system for changing from exhaust steam to live steam operationincluding a valve for controlling admission of auxiliary live steam:

to the injector, a connection providing a path. of flow of steam fromsaid generator to a zone of lower pressure, means responsive to decreaseof pressure in said connection for opening said valve, valve means forcontrolling flow through said connection for varying the pressuretherein,

and means responsive to a decrease toja pre-,

determined value in the pressure of steamsupplied to said consumer foropening said valve means.

4. In a control system for an injector adapted.

to be operated by exhaust steam from a steam consumer and adapted to beoperated byauxiliary live steam when exhaust steam from said consumer isnot available, a valve for control ling admission of live steam to theinjector,

means providing a pressure chamber, means for,

supplying high pressure steam to said chamber, means responsive topressure variations in said chamber for controllin the position of saidiary live steam when exhaust steam from said consumer is not available,a valve for controlling admission of auxiliary live steam to theinjector, means providing a pressure chamber, means for supplying highpressure steam to said chamber, means responsive to pressure drop insaid cham" her for opening said valve, means providing a path of flowfor freely venting said chamber to a zone of lower pressure, valve meansin said path for controlling flow therethrough, and means responsive toa decrease to a predetermined value in the pressure of the steamsupplied to said consumer for opening said valve means.

6. In a control system for an injector adapted to be operated by exhauststeam from a steam consumer and adapted to be operated by auxiliary livesteam when exhaust steam is not available, a valve for controllingadmission of auxiliary live steam to the injector, means providing apressure chamber, means for supplying high pressure steam to'saidchamber, means responsive to pressure variations in said chamber forcontrolling the position of said valve, means providing a path of flowfor freely venting said chamber to a zone of lower pressure-valve meansin said path for controlling flow therethrough, means providing a secondchamber, means responsive to variations in pressure within said secondchamber for operating said valve means, and a conduit adapted to containsteam in static condition for communicating to said second chamberpressure variations of the steam supplied to said consumer. I

'7. In a control system for an injector adapted to be operated byexhaust steam from a steam consumer and adapted to be operated byauxiliary live steam when exhaust steam is not available, a valve forcontrolling admission of auxiliary live steam to the injector, means,pro-. viding a pressure chamber, means for supplyvalve, means providinga path of flow for freely,

inghigh pressure steam to said chamber, means responsive to pressuredrop in said chamber for opening said valve, means providing a path offlow for freely venting said chamber to a zone of lower pressure, valvemeans in said path for controllingffiow therethrough, means providing asecond chamber, means responsive to a decrease to a predeterminedvalueof the pressure Within 'saidsecond chamberflfor opening said valvemeans, and a conduit adapted to contain steam in static condition forcommunicating to said second chamber pressure variations of the steamsupplied to said consumer.

8-. In a control system for an injector adapted to be operated byexhaust steam from a steam consumer and adapted to be operated byauxiliary'live steam when exhaust steam from said consumer is notavailable, a valve for controlling admission of live steam totheinjector, means providing a pressurechamber, means for supplying highpressure steam to said chamber, means responsive to pressure variationsin said chamber for controlling the position of said valve, meansproviding a path of flow for freely venting said chamber to a zone oflower pressure, valve means-in said path for controlling flowtherethrough, means providing a second cham-- ber, means responsive tovariations in pressure within said second chamber for operating saidvalve means, a conduit adapted to contain steam in static conditionforcommu'nicating to said second chamber pressure variations of thesteam supplied to said, consumer, and means for operating said valvemeans independently of the pressure in said second chamber. 7 9. Inacontrol system for an injector adapted to'be operated byexhaust steamfrom a steam consumer and adapted to be operated by auxiliary live steamwhen exhaust steam from said consumer is not available, a valve forcontrolling admi'ssion of auxiliary live steamto the injector, meansproviding apressure chamber, means'for supplying high pressure steam tosaid chamber, means responsive to pressure drop in said chamber foropening said valve, means providing a path of flow for freely ventingsaid chamber to a zone or" lower pressure, valve means in said path forcontrolling flow therethrough, means providing a second chamben'meansresponsive to a decrease to a predetermined value in the pressure withinsaid second chamber for opening said valve means, a conduit adapted tocontain steam in static condition for communicating to said secondchamber pressure variations of the steam supplied to said consumer, andmeans for opening said valve means independently of the pressure in saidsecond chamber. 7

10. In a steam locomotive having an operators cab, a control system foran injector adapted to be operated by exhaust steam from the locomotiveengine and adapted to be operated by auxiliary live steam when exhauststeam from the engine is not available comprising a valve forcontrolling admission of auxiliarylive steam to the injector, meansproviding a pressure chamber, means for supplying high pressure steam tosaid chamber, means responsive to pressure variations in said chamberfor controlling the position of said va1ve, means providing a path forflow of steam from said chamber to a zone of lower pressure, valve meansin said path for controlling flow therethrough, means providing abalance chamber, means for supplying high pressure steam to said balancechamber, means responsive to pressure variations in said balance chamberfor operating said valve means, means for venting said balance chambertoa 'zohe cf lower pressure, a valve for controlling flow through thevent, means responsiveto variations in the pressure of the steamsupplied to said engine for operat'mg the last-mentioned valve, andindependent means for venting said balance chamber to'azone of lowerpressure comprising a conduit having an open discharge within said caband a manually operable valve in said conduit, i

i 11. In a control system for an injector "adapted to be operated byexhaust steam from a steam consumerand adapted to be operated byauxiliary live steam when exhaust steam from said consumer is notavailable, a valve for controlling admission of auxiliary live steam totheinjector, means providing apressure chamber, means for supplying highpressure steam to said chamber. means responsive to pressure variationsin said chamber for controlling the position of said valve, meansproviding a path for flow of steam frorn said chamber to a zone of lowerpressure, valve means in said path for controlling flow therethrough,means providing a balance chamber, means for supplying high pressuresteam to said balance chamber, means responsive to pressure variationsin said balance chamber for operating said valvemeans, means forventingsaid balance controlling flow through the vent, means responsive tovariations in'the pressure of the steam supplied to said consumer foroperating the lastmentioned valve, and independent means for ventingsaid balance chamber to a zone of lower pressure comprising a conduitand a manually operable valve in said conduit.

12. In a control system for an injector adapted to be operated byexhaust steam from an engine and adapted to be operated by auxiliarylive steam when exhaust steam from the engine is not available, a firstvalve for controlling admission of exhaust steam to the injector,pressure respone sive means for operating said valve, a second valve foralternatively supplying auxiliary live steam to saidinjector and to saidpressure responsive means, means providing a balance chamber, a pistonreciprocably mounted in said chamber and'operatively connected to saidsecond valve, means for supplying live steam to both sides of saidpiston, means providing a path of flow for freely venting said balancechamber to a zone of lower pressure, valve means for controlling flowthrough said path, and means responsive to variations in the pressure ofthe steam supplied to said engine for operating said valve means.

13. In exhaust steam injector apparatus, an automatic control system forshifting the injector to live steam operation when exhaust steam is notavailable including a pressure chamber, means placing said chamber inconstant but restricted communication with a source of high pressuresteam and means for setting the control system in exhaust steamoperating position in response to pressure in said chamber, a ventconduit in communication with said chamber, and a manually controllablevalve in said conduit for venting said chamber at will to preventexhaust steam operation regardless of the presence or absence of exhauststeam.

14. In a locomotive having anoperatorscab,exhaust steam injectorapparatus including a steam pressure actuated control system forautomati cally shifting operation of the injector to live steamoperation when exhaust steam is not available and vice versa, saidsystem having a pressure chamber to a zone of lower pressure, a valvefor chamber, means for shifting the system to exhaust steam operatingposition in response to pressure of-steam'in said chamber and a conduitfor continuously supplying high pressure steam to said chamber whensteam is supplied to the engine of the locomotive, a vent conduitcommunicating with said chamber and having its discharge end located insaid cab, and a valve operable from the cab by the operator forcontrolling flow through said conduit. v

15. In a locomotive having an operators cab, exhaust steam injectorapparatus including a steam pressure actuated control system forautomatically shifting the injector from exhaust steam operation to livesteam operation when exhaust steam is not available and vice versa, saidsystem comprising a vent conduit adapted to be opened to preventshifting of the system to exhaust-steam operating position,.said conduitbeing-in communication with a source of steam when the system .is inlive steam-operatingposition and having its discharge end located insaid cab, and a valve operable from the cab by the operator forcontrolling flow through said conduit. '16. In a steam pressure actuatedcontrol sys-v tem for exhaust steam injectors, means providing apressure chamber,- means for supplyingactu-. ating steam to saidchamber, an element responsive to pressure in saidv chamber for shiftingthe system to exhaust steam operating position, a first conduit forventing said chamber. to shift the system from exhaust steam operatingposition, a valve for automatically closing said conduit une derpredetermined operating, conditions, a second conduit for venting saidchamber, and a manually operable valve in said second conduit-adaptedtobe opened to render the automatic closing of the first-mentioned valveinefiective to shift the system to exhauststeam operating position.

17. In. exhaust steam injector apparatus, 1 a steam pressure actuatedcontrol system for an.- tomatically shifting the injector .from exhauststeam operation to live steam operation when exhaust steam is notavailable and vice versa in-, cluding a pressure chamber in continuouscommunication with a source of high pressure steam when steam issupplied to the engine from which exhaust steam is derived for injectoroperation, a vent conduit in continuous communication with said chamberand said source for venting said chamber to prevent shift of theinjector to ex-, haust steam operation, and a manually operable valve insaid vent conduit.

18. In a locomotive, exhaust steam injector api paratus including asteam pressure actuated control system for automatically shifting theinjector from exhaust steam operation to live steam operation whenexhaust steam is not available and vice versa, said system including apressure chamber and means responsive to pressure in said chamber forshifting the injector to exhaust steam operation, conduit means placingsaid chamber in continuous communication with a source of high pressuresteam when steam is admitted to the engine of the locomotive, wherebythe injector is normally shifted to exhaust steam operation when steamis admitted to the engine, a vent conduit for continuously venting saidchamber of the steam admitted thereto from said source, and a manuallyoperable valve for opening said vent conduit.

19. In a locomotive having an operator's cab, exhaust steam injectorapparatus including a steam pressure actuated control system forautomatically shifting the injector from exhaust steam operation to livesteam operation when exhaust steam is not available and vice versa, saidsystem including a pressure chamber and means responsive to pressure insaid chamber for shiftingthe injector to exhaust steam operation,conduit means for placing said chamber in continuous communication witha source of high pres sure steam when steam is admitted to the engine,whereby the injector is normally shifted to exhaust steam operation whensteam is admitted to the engine, a vent conduit in continuous communication with said chamber and having an outlet located in said caband a valve manually operable 'from said cab for opening said conduitwhereby to vent said chamber to cause the injector to be operated as alive steam injector regardless of the presence or absence of exhauststeam and to continuously conduct to the cab high pressure steam fromsaid source when exhaust steam is available and the injector is operatedas a live steam injector due to the opening of said vent conduit.

' EMANUEL RAWSON.

